Delayed decision-making by clients can be (but certainly is not always) an important signal that something may be amiss.
Clients will often not reject directly an unacceptable proposal and may instead defer direct communication in order to not lose your face. In the case of a proposal that is to be rejected for any number of reasons, senior client members may offer a range of various difficult to deal with objections. A series of seemingly peripheral but difficult to solve objections is often intended as a clue that a proposal has been or is on the way to being rejected. Dogged persistence in the face-to-face meeting is, in this case, ill-advised as it will be perceived as an effort to place the counterpart in a situation requiring him or her to violate his or your mianzi. A better approach is to summarize this portion of the discussion by asking for commitment from the senior counterpart to support follow-up between your and their lower-level staffs.
In other cases answers may not be forthcoming for a range of reasons. The client senior manager may not know the answer; he may need more information (but may not ask directly due to mianzi concerns); he may not have the authority to make the decision and may need time for internal discussions with supervisors; he may feel a need to consult with his staff to gain consensus and buy-in. All of these concerns, if discussed openly, have the potential create loss of face for the client-manager. As above, it is best in this case to state clearly the question or concern, why it is important, and ask for commitment for the staffs to resolve the issue in “off-line” meetings in the near future.
It is often completely acceptable to ask for a due date allowing reasonable time for the types of underlying concerns to be addressed by the client. In this case you gain commitment for internal action by the client, so that you may expect better information in the near future.
Increasing pressure for immediate answers is almost never the correct approach.